Chemoembolization for Hepatocellular Carcinoma in Patients With Inferior Vena Caval/Right Atrial Tumor Thrombi Without Hepatic Vein Invasion

Abstract

Aim: To clarify the clinical and radiological features of isolated tumor thrombi in the inferior vena cava (IVC)/right atrium in patients with hepatocellular carcinoma (HCC) without hepatic vein invasion. Patients and Methods: In this retrospective study, from January 2007 to December 2019, a total of 35,163 chemoembolization sessions were performed in 7,704 patients with HCC. Among them, 10 (0.13%) patients had tumor thrombi in the IVC/right atrium without definitive hepatic vein invasion. Computed tomographic (CT) scans, digital subtraction angiograms, and cone-beam CT images were retrospectively reviewed and interpreted. Results: The tumor thrombi were supplied by the right inferior phrenic artery (n=8) or the right internal mammary artery (n=2). Follow-up CT scans in eight patients showed linear accumulation of iodized oil along the diaphragm, which was presumed to be a thrombosis of the phrenic vein. Retrospective review of formal radiological reports of pre-procedural CT scans revealed that a correct diagnosis of tumor thrombi of the IVC/right atrium was made in only three cases. Conclusion: HCC invading the phrenic vein may have tumor thrombi in the IVC/right atrium without hepatic vein invasion.